terminal segments of Halticella, d-c. 303 



the terebra protruding between them. The hypopygiiim, 

 and the terebra with its adjuncts are shown disengaged 

 from each other in figs. 11 and 12. The apex of the 

 former highly magnified (fig. 13) has been casually severed 

 along the carinated ridge, where no suture exists ; but 

 being brittle and deflexed around the sheaths, when 

 these are withdrawn from the longitudinal channel below 

 it readily yields along this line, as here exhibited. The an- 

 tenna of the female (with which that of the male closely 

 corresponds, on a smaller scale) is shown in fig. 14 ; 

 the fore and hind wings in figs. 15 and 16 ; and the 

 posterior leg, in the same sex, with its incrassated in- 

 ternally serrate femur and minute tibial calcaria, in fig. 

 17 ; a similar structure, without the serrate margin, 

 existing in the male. 



With respect to the old genus Chains, our honoured 

 colleague states that, after vainly seeking to discover some 

 better definitions between this and Pluisganopliora than 

 the unisexual character of the caudal appendages in the 

 latter, he had unexpectedly been led to a conviction 

 directly contrary to his expectations, compelling him to 

 unite those genera together, as presenting intermediate 

 transitions which rendered it difficult to determine the 

 respective limits of each. Having come to this con- 

 clusion, he soon found that similar transitions among 

 the species of the genus Conum irresistibly led to their 

 absorption in like manner; some with Chalcis, and 

 others, having a petiolated abdomen, being readily 

 affiliated to the genus Smicra of Spinola ; while the 

 genus Halticella of Spinola, having the antennae inserted 

 near the mouth instead of at the vertex, served as a 

 rallying point for others detached from Phasganophora. 

 Thus, as M. Andre explains, " les trois genres Chalcis, 

 Smicra, et Halticella, renferment chacun une serie 

 d'especes a segments posterieurs de I'abdomen prolonges 

 plus ou moins, quelquefois d'une facon demesuree, mais 

 sans que Ton puisse les separer d'une facon nette de 

 toutes les autres" (p. 337). 



No satisfactory result has thus been obtained by dis- 

 regarding the characters of the terminal segments ; and 

 in fact, when limiting these subdivisions to tlircc — whose 

 prominent attributions are equally unstable, and involving 

 therefore the same inherent defects — the arguments 

 propounded as aforesaid must be no less available to 

 debar these groups from any such privileged exemption. 



